My wife's 122K mile '99 STSpower steering seems to work fine when cold, but after warming up it is hard to steer in a parking lot, and is getting worse around tight corners when driving, both left and right.

Is this likely a pump problem or a rack problem? I believe if it ishard to steerone way and not the other, the rack is the likely culprit, but I'm hoping since it is the same both directions that my pump is worn out because I did a rack on my '94 SLS and that's not fun. Also, the price of a pump is half the price of a rack.

 

I had flushed the power steering system once before, but it was already brown and smelled burnt. Installed a new pump yesterday, flushed it by having my wife turn it from center completely left and right twice and back to center while I poured almost a gallon of PS fluid in while the return line was dumping through an old piece of garden hose into a catch pan. Now it's nice and clear and smells nice again, and it is no longer stiff to turn in a parking lot when hot. Success!